Selective signaling and control system



SELECTIVE SIGNIALINGAND CONTROL SYSTEM Filed April 16. 1928 ATTORNEY. Ffa! Jan. 31, 1933. E. E. KLEINSCHMIDT 1,895,718

SELECTIVE SIGNALING AND CONTROL SYSTEM Filed April 16. 1928 3 Sheets-Sheet 2 202 w; 19.52% a.; of .MM/M.. 42105' f f, ,v INVENTOR.

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I E. E. KLElNscHMlDT 1,895,718

SELEGTIVE SIGNALING AND CONTROL SYSTEM Jan. 31, 1933.

s sheets-Sheet :s

ATTORNEY.

iF/T- Filed April 16. 1928 l UNITED STATES y Patented Jan. 31, 1933 Bassum PATENr oFFlcE EDWARD E. KLEINSCHMIDT, OF CHICAGO, ILLINOIS, ASSIGNOB TO TELETYPE CORPO- 4RATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE sELEe'rIv-E sIeNALrNe AND CONTROL SYSTEM Application led April I16, 1928. Serial No. 270,385.

My present invention relates to selective signaling and control systems, and more particularly to the selective control and supervision for a control station of devices such lfor example as circuit breakers, motors and the like located at a point remote from the first station.

The development of large electric power systems in recent years has been in the direction of replacing the few large sized sub-stations in a system by a large number of small sized sub-stations scattered over an electrical system in accordancewith the power require changes in power conditions has, therefore,-

been developed. As a result, most present day operating sub-stations particularly on electriied railway systems are now entirelyl unattended, the circuit breakers and other power units located therein being operated `automatically in response to such changes as load voltage and current.

While such automatic equipment has been found to be satisfactory for performing the necessary operations while normal conditions exist in the power system, it has been found impractical to develop automatic equipment which responds to abnormal conditions, such for example as serious short circuits of la persistent nature, and excessive power' demands for short periods on one power circuit. Such abnormal conditions are not, however, unusual and must be properly taken care of.

In order to render the power system suiiciently flexible to take care of all conditions there has developed in recent years manual remote controls, now known as supervisory control systems in which signaling circuit connections are made between a dispatching otce located in the central generating station and each of the automatic sub-stations, whereby the dispatcher can selectively control each of the automatic circuit breakers or other apparatus units.

The system is also provided `with answer back equipment which operates in response to the operation of any one of these units for giving the dispatcher an indication of the condition of the unit. In this manner, he is apprized at alltimes of the condition of all the units and can at all times selectively operate any -one of the units at any one of the stations. There is thus provided an automatic system with manual control superimposed meetingV the commercial necessities of the former and the flexibility. inherent in the latter. l

Accordingly, it is an object of my invention to provide means forselectively controlling and supervising remotely disposed power apparatus units from a central dispatching ppint which is simple, inexpensive and relia- Another object of my invention is to provide simple and inexpensive code responsive telegraph equipment for selectively conditioning remotely disposed -power equipment units for direct control by a dispatcher and;

for providing thedispatcher with indications of the operations o'f these units.

Still another object of the invention is to provide a mechanical selector in a supervisory control system for identifying the remote i selection made .so that the dispatcher is assured of the particular operation he .will make before an operation occurs.

' Other ob]ects of my invention will appear in the following detailed description of the preferred embodiment of my invention, and are such as may be attained by utilization of the various principles, combinations and subcombinations hereinafter set forth and defined by the terms of the appended claims.

In the drawings- Figure 1 is a diagrammatic view ofthe circuits and apparatus at a dispatchers oice.

Figure 2 is a diagrammatlc view of the circuits and apparatus at a sub-station.

Figure 3 is a perspective view of a preferred form of selector receiving apparatus at a sub-station. l

Figure 4 is a view partly in section of the notched bars employed in the receiver.

Figure 5 is a perspective view of the re- -which operates in response to an operation thereof for transmitting a code to the dispa-tchers office in accordance with said operation. I

Figure 7 is a perspective View of the keyboard transmitter employed by the dispatch'- er for transmitting the code to selectively opcrate the remote unit.

Figure'8 is a side view of a locking device for locking any operated selected lever in V- operated position and the non-operated selector levers in non-operated position.

. `As shown in Figures 1 and 7 a keyboard comprising a plurality of key levers, 1 have upturned front ends 2 pivotally supported at '3 to a lever carrying member 4 which is properly secured to the frame of the transmitting apparatus. A spring 5 engaging each key lever 1 at an indent portion 6 thereof, yand secured at its opposite end to the frame work at 7 normally maintains the lever 1 in its normal and non-operating position.

In co-operative relation with each of the key levers 2 are a plurality of longitudinally p slidable bars 8, provided with bevelled lugs 9. As is well understood by those skilled in the art, when a key lever 1 is moved to its operated position against the action of compressing spring 5, the lower edge of the key lever engages the cams or.bevelled portions of certain of the bars 8 and the further downward movement of the key lever 1 moves certain of these bars 8 longltudinally in either direction depending upon the slope of the bevelled portion engaged. vIn this manner, the keys when operated serve to set these bars in different combinations. At its right hand end, each permutation bar 8 is 'provided with a notch 11 in its upper edge which engagesl the rounded lower 'end of a corresponding selecting finger 12. The selecting fingers 12 extend upwardly through an opening 13 in the base frame 14.and are mounted upon a common pivotal support 15 arranged between uprights 16. The fingers 12-.control a set of switch shi-fters in the form of bell cranks 17 mounted upon a horizontal pivot shaft 18 carried'by the upright 16. Each selectingv finger 12 has aphook lug 19 at its upper end, whlch as the associated permutation bar is shifted, is moved into or out of engagement' position above the ends of the horizontal arm of the associated' switch Shifters 17. The fingers 12 and bell cranks 17 are held in proper position by spacing washers (not shown) and preferably a guide comb (not shown) is also provided for the horizontal arms of the bell cranks orswitch Shifters 17. In addition tothe switch Shifters controlled by the permutation bars, an additional switch shifter 21 is provided not controlled by the selecting fingers. The contacts of this shifter are normally closedand are opened upon 'lug 25 onthe horizontal arm of the corresponding switchl shifter in engagement with the surface of a cylindrical cam 26, the latter being mounted on a horizontal shaft` 27 extending abovev the horizontal arms of the switch shifters or controllers 17. The cam 26 is provided with a helical series of slots of vwhich one slot 28 is shown and which as the cam 26 is rotated, successively pass over the .lugs 25 of the switch controllers 17. As the corresponding slot passes over one of the lugs, its associated switchcontacts are closed provided the horizontal arm of the switch controller 17 is not held down by the corresponding selecting finger.

The shaft 27 is'journalled in bearings (not shown) in the frame'. Normally the cam 26, which is frictionally engaged by the shaft 27 is prevented from rotating therewithv by means of la stop mechanism (not shown) which isl controlled by the key levers 1 to release the disk in a manner Ldescribed in detail in patent to Krum--1,595,47 2, issued August 10, 1926,in1which is also found a clear description of the specific manner of mounting the shaft 27 and the cams herein illustrated diagrammatically. Inasmuch as the 'specifc details of this construction do not constitute part of the present invention, they are merely described in general.

Y Fingers 12 are provided at their upper ends with upwardy projecting lugs 32 having bevelled upper edges which cooperate with a bevelled rib 33 on a locking bail 34. The latter is Apivotally mounted at 35 on the upright 16 and a spring 36 secured thereto and the upright 16 tends to depress the lock bail and to hold a roller 37 thereon in engagement with the dwell portion 38 of the transmitter cam 26. A lug 39 on the cam engages the roller 36 during-the zero or' normal arrested position of the transmitter cam and thus holds the lock bail 34 in raised position against the tension of spring 36. Shortly after the cam starts, the spring 36 vdepresses the lock bail and holds the selecting fingers 12 and permutation bars 8 in set position and since each bar has an inclined surface co-operating with each of the key levers, non e of the key levers I 35 normal disengagement position.

except the one depressed can be operated. un-

til the lock bail is raisedto release fingers 12. As shown in Figures 1 and 7, each lever 1 is provided with a key lever lock n41 pivoted atA 42. The upwardly extending arm 43 is forced into engagement with the end 2 of its -associated lever at lug 44 by spring 45. The

. naling line between the dispatchers oilice and sub-station from connection with the transmitter at the dispatchers otlice to connection with the receiver. This circuit is thus switched when the transmitter has completel ly operated. When any key lever 1 operates,

lug 44 on the associated latch slips over the upper edge of the key lever and locks the key in operated position. At the same time, contact 47 engages contact 48 to prepare the circuit referred to above. A universal restoring bar 49 secured to armature 51 by screw 52 engages the horizontally projecting arm 53 of the lock lever operated to restore 1t to its normal position. Armature 51 is operated by magnet 54, the circuit for which is completed overcontacts 55 and 56 associated with the restoring key lever 57. When key lever 57 is operated, magnet 54 is operated and rocks armature 51 which in turn operates the universal bar 49 into engagement with the horizontal arm of the operated lock 'lever to restore the same and its associated key lever to As is well understood by those skilled in the art, the transmitter cam `26 is divided into seven sections of which one is shown in its operated position, when the cam 26 is in its arrested normal or zero position. The contact 21 of its associated switch controller 21, is accordingly closed to normally hold the line closed. Operation of any key lever 1 will release the cam 26 for rotation. As the cam 26 rotates, the switch controllers 17 will be variably operated as thesucceeding sections of the cam 26 pass through the operated position, in accordance with the setting of ,the permutation bars to close or hold open the other pairs of contacts 23 and 24 during the five selecting intervals of the signal. At the end of the signal'and before the cam is arrested, the switch controller 4will invariably restore the line to no current which will normally maintain a stop condition as the first 'section of the cam is again moved intoA operating position. l The lug 39 releases the lock bar 34 before the transmitter cam 26 is arrested so that if the keys 1 are rapidly operated the transmitter cam can be continuously rotated to transmit the signals to the line. under such conditions, the signals will be separated by intervals of normal line conditions which prevail as the first 1section of the But even 'cam member passes through the operated position so that ample opportunity is afforded the cams of the receiver .to reach normal or zero position at the end of each signal before the starting condition of the succeeding vsignal is impressed on the ling.

As illustrated, if the transmitter contacts are connected directly to the line, the latter is normally closed. The starting interval is. one of no current and the selecting signals are permutations of current and no current intervals.

When a key lever 1 is moved to its operated position it will engage the cam surfaces 9 of the permutation bars 8 to move these bars longitudinally either to the right or left, depending upon the slope of the cam surface 9 of the bar when engaged `by the key lever 1. `These will, in turn, rock certain of the selecting bars 12 about their pivots 15 counter clockwise to engage their associated switch controllers 17 through lugs 19. This movement of a key lever 1 also releases'the cam 26 which is then rotated with the shaft 27. Upon the first movement of the shaft 27, the lug 39 releasesthe locking bar 34 which thereupon engages the lug 32 to lock the selecting bars 12 in their operated or nonoperated positions. These bars cannot, therefore, be operated by any other key bar `1 during the si gnalingperiod. As the cam 26 then continues to rotate and the lugs 25 enter their cam depressions 28, successively, the successive switch controllers 17 are either released for operation or held in non-operative position by the lugs 19 engaging the switch controllers 17, to in-turn close the' contacts 23 and 24. y f As the contacts 23and 24 are successively closed, a circuit is completed from ground at 61 through battery 62 through the contacts 24 and 23 over the conductor 63, back contat-t and armature 64, through the vline polar relay 65 over conductor 66 connecting the dispatchers ottce and sub-stations through the polar relay 67,I conductor 68, armature 69, and its back contact over conductor 71, a second sub-station through the.

polar relay 72 thereat, armature 73 and its back contact over conductor 74 to ground 7 5.

The normally biased polar relay 65 connected in the line circuit at the transmitting station comprises a pair of windings 76 and 77 and armature 78 normally heldin a biased position in engagement with its left hand contact by the spring 79 as shown. The impulses from battery 62, however, are of such polarity as to operate armature 78 out of engagement with its contact, but,as will be explained hereinafter, this operation of relay 65 hasno effect at this time.

At the sub-station, a similarly constructed polar'relay 67. comprising a pair of windings 82 andV 83 and a biased armature 84 held by spring 85 'is provided. As will appear fies from the description to follow, with er-iergy inthe line from battery 62, the armature 84 is held disengaged from its contact. When, however, batteryis removed from the line due to a start operation at /the transmitter opening the line 21, spring 85 moves armature 84 to engage its contact. This opera- ,I

tion of armature 84 completes an energizing circuitl for receiver magnet 85 controlling a receiver at the sub-station to select an operating circuit for an apparatusunit.

The receiver magnet 85 operates an armature (not shown) to release and shift a cam shaft 86 axially during its rotation in a manner described in detail in patent tov Kleinschmidt, 1,567 ,392 issued December 29, 1925.

The cam shaft 86 is of the pin barrel type de-` scribed in detail in the above referred to patent. A number of cams 87 to 91 are axially spaced along the shaft 86 so that when the selector magnet 85 is energized, and the cams l leases the shaft 86 for rotation by permitting the armature 84 to engage its contact andl 'thereby establish the circuit over line 211 'fingers 92 to 96 in one or the other of their positions through the instrumentality of their associated cams 87 to 91. The actuated ones of these fingers are locked in actuated position by the latches 97 individual to each of the fingers 92 to 96. When the fingers 92 to 96 have been completely set, selected ones of notched permutation bars 102 to 106 are permitted to move to selected position under the influence of` springs (not shown) in accord'- ance with the setting of the fingers 92 to 96. Immediately thereafter the selector fingers are in condition to be reset. The cam shaft 86, it will be understood, is driven through a friction clutch from a shaft (not shown) which is in turn driven by a continuously rotating motor (not shown.) in the manner described in detail in the above referred to patent.

As is well understood, the various combinations of selector bar positions bring into alignment different combinations of the notches thereof, and a selected actuating bar 107 positioned directly thereabove is permitted to drop, in the manner described in the above mentioned patent.

A series of these actuating bars 107 extending through guide plates (not shown) .are arranged to co-act with the selector bars 102 to 106 to effect the desired selection. Each bar 107 is provided with a cam projection 108 and a shoulder 10-9. Certain of these actuating bars are pivotally connected to the circuit selecting bars 112 which are operated thereby to effect the desired selection of aA power apparatus unit. The actuating bars 107 are connected to the operating bars 112 by means of pins 114. It will be apparent that movement of the actuating bar 107 to the right will rock the operat-ing bar 112 clockwise about its pivot 116 carried on the support 118 on the framework.

Cam surfaces 108 on the actuating bars 107 are held by springs 120 against a universal bar 122 supported in member 124 which align a set of notches, the member 124 is permitted to move forwardly as the bail frame moves forward, all of the actuating bars 107 are permitted to drop as the bar 122 passes from under cam surfaces 108 held in engagement with the member 122 by action of the springs 120. Since, however, only one set 0f slots may be aligned by each setting of the selector bars, all of the bars 107 except the selected one above the aligned notches are brought to rest by striking the selector bars, while the selected one drops far enough to permit engagement of the shoulder 109 with the operating bar 128.

The particular bar 107, over the aligned slots will continue to drop until it has entered therein when the continued movement of the operating bail frame 124-will cause the operating bar 128 to engage the shoulder 109 and will move this selected actuating bar 107 forwardly. The forward movement of the selector bar 107 will rock the circuit selecting bar 112 about its pivot 116. After the operating stroke of the selected actuating bar 107 has been completed, the operating bail 124 is moved in the reverse direction as described in the above referred to patent, and as it passes over the cam surface 108, it restores the selected bar 107 to normal.

The operating bar 112 is provided with a lug 129 which normally is engaged by the locking member 130 ypivoted at 131 and urged into engagement with the lug 129 by the spring 132. Each of the operating bars 112 is provided with a horizontal arm 133 for controlling -a contact member l134 individual thereto and properly insulated therefrom. Normally, the bar 112 is in the position shown, and holds the contact member 134 in disengagement from the stationary contact 135. When, however, the bar 112 -is rocked about its pivot in the Amanner described above, the contacts 134 and V135 are closed. Similar contact members 136 to 138 are here illustrated, it being understood that each of these contacts is controlled by a similar operating bar 112, each contact in turn preparing an operating circuit for an individual power apparatus.

When the operating bar 112 is rocked about its pivot 116 in the manner described above, the locking bar 130 in co-operation therewith drops behind the lug 129 under the influence of the spring 132 and locks the selected bar 112 in operated position. This same movement of the locking member 130 through veX- tension 141 rocks the bell crank 142 about its pivot 143 lto shift the contactor 69 from engagement with its left hand contact 144 to engagement with its right hand contact 145.

It will be recalled that in thel circuit traced above from the dispatchers oliice to the substation, the circuit was completed through .the contactor 69 and its Contact 144; As a result of this switching operation, however, following the selection of bar 112 the signaling circuit from the transmitting station or dispatchers oilice is switched from a selecting to an operating position. for operating the selected unit in the manner which is nowto be described.

- `Each of the circuits controlled by the in.-

dividual contacts. such as 134 and 135 has associated therewith an apparatus unit which is to be controlled. In the present illustration, a single circuit breaker is shown, al-

though it will be understood of course, that this is merely illustrative, and that similar circuit breakers and other power apparatus units may be controlled over the other selecting circuits completed by the other contacts illustrated. The conductor 146 connected to the contact 134 is also connected lto the triping magnet 147 associated withI the circuitreaker 148, the other terminal of the tripping magnet 147 being connected over conductor 149 and battery 151 to armature 152 of polar or operating magnet 1,153. The polar or operating magnet 153 comprises, in addition to the armature 152, windings 154 and j1'55, the armature 152 being normally biased byspring 156 in the position shown. n The contact 157 with which armature 152 engages when the polar relay 153 is energized by currents of a predetermined polarity, is connected over conductor 158 to the stationary c contact 135 co-operating with contact 134.

The power apparatus unit 148 here illustrated, comprises, in addition. to the tripping coil 147 which through the pivoted lever arm 167 trips the circuit breaker, a closing coil 168 for moving the arm 169 to enga e their power contacts. A toothed .rack 1 1 connected to the circuit breaker arm meshes with a pinion 172 mounted on spindle 170 which carries rotatably therewith a cammed disk or break wheel 173. A helical spring 172l one end of which is secured to spindle 170, and the other to break wheel 173 is tensioned by rotation of pinion 172 to rotate wheel 173, Fig. 6. A regulator 173 controlling pinion 174 meshes with gear 175 carried on shaft 170` and controls the speed of operation of disk 173; A contact controller 174 pivotally mounted at 175 is 'forced into engagement with the cammed disk 17 3 bythe spring 17 6.v

hereinafter. ferent type of cammed disk 17 3-is provided lbreaker in a manner to be described in detail I t will be understood that a diffor each circuit breaker so that on operation i each sends a different code combination of impulse conditions'. It will be noticed that the breaker wheel 173 is equipped with a plurality of cams irregularly disposed so that upon tripping the circuit breaker 148 one sequence of signal may be produced while upon closing the breaker, the wheel 173 travels in the reverse direction and another sequence of signals may be produced.

It will be noted that the circuit selecting member 112 in addition to closing'the contacts 134 and 135 is provided at its opposite extremity with a downwardly extending portionv 182 which engages a series of cammed permutation barjs3183 to 187, as shown in detail inFigure 3. v The bars 183 to 187 comprise a code transmitting apparatus at the sub-station similar to the code transmitter operated'by the keyboard bar lat the dispatching office described in detail above and need not, therefore, be again described. Each of the members 112, when selectively operated,`

will move the permutation bars 183 to 187 longitudinally infdiferent combinations to in turn cause closing of dili'erent combinations of the contactors 188 under control of the s'witchactuating member 191 as the cam shaft 192 rotates. It will be understoodthat there are a number of these contacts selectively closed as described in connection with rthe transmitter at the dispatchers oliice. Cams 193 are radially notchedy about cam shaft 192,

tending sequentially to permit the movement of those bell cranks 193 which are not locked by the lugs 194 on selecting' bars 195. The

selecting bars 195 are held in operated or nonoperated positions by-lugs 196 engaging the locking bars4 197 after the roller 198 has l passed over the camv projection 199.

The construction and operation of the transmitter at the sub-station is identical from ground at 202 through the coil 203, conductor 204, contacts 180 and 179 in engagement, over conductor 205 through the contacts 202 and 201, conductor l206 through the relay 153 over the Contact 145, andcontactor 69 which, it will be recalled, isthen in engagement with its right hand contact over conductor'68 through Iline relay 82, conductor 66, relay 65 at the dispatchers-oiiice, armature 64 and its back convtact, conductor 63, contacts of bell crank `21 and battery 62 to ground at 61. Upon operation of member 112, members 183 to 187 are uoperated 1n various combinations to in turn operate their individual levers 195 and at -the same time shaft 192 is released for rotation all as described in connection with the control station transmitter. Thereafter a code is transmittedov'er this circuit from the substation to the dispatchers station in acl'--cordance with the selected member 112 to indicatel to the dispatcher whether or not its selection was proper..

At this time, operation of relay 82 has no effect on the receiver magnet 85 at the subistation inasmuch as its circuit is opened at. contact 211 by the rotation of cam 212. The transmitting cam shaft 192 is connected to disk 212 so that when it starts into rotation the disk 212 is also rotated and contact enga'glg arm 213 disengages the contact 211. w a result of the operation of polar relay 65 at the dispatchers oice, armature 7 8 en- Y ages its contact to complete a circuit for the magnet 215 over a circuit from battery 216, conductor 217, the armature 78 in engagement with its contact, conductor 218 ylngers224ino through the contacts 219 and arm 220, conductor 221, and through the operating magnet 215l to the battery 216. Theoperating 'magnet 215 operates selector equipment similar in construction tail at the' sub-station. 'A pin barrel selector 223 is normally held from rotation by a 'constantly drivenmotor shaft and is released -by the first energization of magnet 215. As the selector 223 rotates,it is successively `operated by magnet 215 to position selector fingers 224 w 1l set permutation bars 227 -to in turn condition one of the operating bars 228 for operation by operating member 229. The movement of operating member 229 in turn rocks selector member 231 about its pivot 232. An individual pivoted latch- -ing lever 233 mounted above a universal bar erated position. The selector,

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operated fingers 224 are latched by the in? vdividual pivoted members 225 which drop in front of the projecting lugs 226 under operation o springs 227 selected bar 231 will also operate a contact 233 into engagement with the contact 234.

Inasmuch as -each of these contacts 233 is connected over an individual conductor such as 236, to its contact 47 controlled by its associated key lever 1, it will be clear now that this circuit including the relay 236 will not be completed unless the received code in'- dicative of the selection made at the substationis similar to the particular operated key bar at the dispatchers office. If such is the case, a circuit will be completed from the 231 thus apprizes the dispatcher of the corposition, le-` 1, to the opposite terminal of The operation of the rect selection inasmuch as the code transmit- Y ted from the sub-station to which the receiver at the dispatchers oiflce responded was proof that the particular selector bar 112 selected at the sub-station as a result of -the code transmitted thereto, by the operj 'ator from the dispatchers olflce was correct.

to that describedin de- If the dispatcher now desires to operate the selected unit, it is only necessary to operate the key 239 to engagement with its contact, w'hereupon a circuitv is closed from ground through the battery 241 over the-key 239, relay 247, the front contact and armature 64 to the polar line relay 65, conductor 66, polar line relay 82, armature 69 and its contact 145, to the operating polar relay 153, conductor 206 to normally closed contacts 201 and 202 of the transmitter, conductor 205,

`contacts 179 and 180, conductor 204 .and

ound at 202. It will be noted that the poarity of this operating impulse is opposite from that of the code; signals and accordingthe polar line relays 65 and 82 will merely Vtend to maintain their respective armatures in the bias position alreadylmaintained by their springs, and accordingly no operations will occur at these polar relays. The operating relay 153, however, is arranged tov reles spond to this operating impulse to move its armature 152 from its biasing position maintained by spring 156 into engagement with its contact 157, and a circuit is thereupon completed for the lparticular selected unit. In the present case, the circuit for tripping solenoid 147 has been prepared and will now be completed from the battery 151 over conductor 149 through the tripping solenoi d 147 conductor 146, through the contacts 134 an 135 in engagement and over conductor 158 to the contact '157 and armature 152, and then to the opposite terminal of thebattery 151.

As a. result of the energization o the tripping solenoid 147, the circuit breaker 148 will be tripped. As the circuit breaker moves, break wheel 173 is Vrotated to operate the contact lever 174 making contacts 177 and l17 8, and breaking contacts 179 and 180. It

relay 153, contact 145, and armature 69 conductor 68 through polar relay 82, conductor 66 polar relay 65, at the dispatching oiiice to armature 64 and its right hand `contact through the relay 247, key 239, and battery 241 to ground.

It will be noted that in this circuit, batteries 246 and 241 are connected in series relation and accordingly a larger current will How in this answer back signal than in the case of the control operation. The relay 247 is marginal and will not respond to the normal operating current transmitted by the battery 241.r When, however, the batteries 241 and 246 are in series relation as in the above circuit, sutlicient eurent flows through the relay r247 to operate it. As a result of the operation of relay 247, armature 248 in turn completes a circuit for the recorder 249 through battery 251. The recorder of any well known type is operated in accordance with the particular circuit breaker which has operated and the dispatcher is thus apprized of the particular unit which has operated and the manner of its operation.

It will be recalled from the above description that the selected operating bars 112 and 231 at the sub-station and office when operated, are locked in selected position and remain so until released by the operation of a special release key 57 at the dispatchers ofiice. In the present instance the restoring key 57 operates the notched bars 8 and simultaneously completes energizing circuit by the movement of the movable contacting member y 56 into engagement with the contact 55 for the energizing magnets 54 and 255, the circuit being completed from battery 256 to the magnet 54 and magnet255 in series over the conductor 257, the contact 56 in engagement with contactor 55 to the opposite terminal of the battery 256. As a result of the energiza.- tion of the magnet 255, its armature 258 carrying a lug ,259 on the end thereof, engages the lever 233 and moves it upward against the tension of its spring 235. Lock bar 234 is restored Aand releases operating member 231 which Vreturns it to its normal position. Energizat-ion of magnet 54 operates its armature 51 to swing transversed bar 49 against projection 53 of the operated locking lever which is thus restored to release key lever 1. Simultaneously, the contact 47 disengages contact 48^and as a result, the energizing circuit forthe relay '236 vis opened and the larmature 64 dro-ps to engagement with its left hand contactpreparing a circuit for the selector codes from the transmitter. The bar 57 as noted above, also operates a predetermined combination of the notched selecting bars 8 which inthe manner described above transmit a special restoring code combination ofyimpulses to the substation. During the transmission of this cdde of impulses as in the case above, contacts 220 and 219 separate so that operation of the ,polar relay l65 is not eii'ective to release the local magnet 215. Polar relay 82 at the sub-station, however, moves its armature 67 into engagement with its contact completing an energizing circuit forreceivingmagnet 85.

A predetermined combination of selecting bars 102 and 106 are operated in accordance with this special restoring code to select an operating bar 260 associatedl with the lever arm 261. normally urged to itsnon-operating position by the spring 262. When the bar 260 is operated, it rocks the bar 261 about its pivot 263 and its lug 264 engages the projection 265 of the lever 130 which is thereupon rocked about its pivot 131 against the tension ofspring 132 to release the operated bar 112 from its locked position. Bar 112 is thereupon restored to its normal position and opens the contacts 134 and 135. In this manner the apparatus is restored to normal following the operation of the selected unit and the answer back with this operation.

From -the above, the operation of the apparatus should now be clear. `*When the operator at the dispatchers oilice desires to operate any desired -selected power unit, he will operate a key bar such as l for transmitting a code in accordance with the particular unit which he desires to operate. The transmitting and receiving apparatus at each of the stations is normally in a non-operating position. When the key bar is operated, the transmitter at the dispatchers office is started into operation and transmits a predeterminedcode of negative and no current polarity as indicated by the terminal markv, to release its pin barrel selector. ingly, the transmitter at the oiice and receiver ings of battery 62. Simultaneously, the par' ticular operated key bar 1 and selecting bars 8 respectively are all locked in their operated position to prevent the operation of any other key or transmission of any other code at this time. key bar 1 in addition to transmitting the code, also prepares an operating circuit for the rel lay 236 at contact 47 which circuit is comipleted only when the correct code has been re- Accordsub-stations always start substantially, simultaneously insuring synchronous operation. The magnet 85 now operates according to the code to select the particular operating bar 112, which Will prepare a local selecting circuit to the particular unit which it is desired to be operated. A further result of the energization of this particular selecting bar 112 is also to operate a transmitter at the substation similar in construction and to ythe operationof the transmitter at the oilice. This selection, therefore, not only results in the preparation of an operating cir` cuit at the sub-station,'but will also start the code transmitter into operation which upon its lirst movement opens a local circuit to the magnet 85 at contact 211 .and also transmits a code of impulses to the-dispatchers 'oilice. This code combination ofimpulses, it will be understood, depends upon the particular bar 112 which has been selected.

When the code is received at the dispatchers oiiice by the polar magnet ,65, `the circuit for the receiving magnet 215 is completed inasmuch'as the code transmitter at the dispatchers oflice has completed its operation andV is restored to normal and ,the contacts 219 and 220 are again in engagement. The

r receiverwillbe'operated to select an operating bar suchvas *231.` Inasmuch as each of the selector bars 231 completes a circuit to an individual operating key bar 1, lwhich has, as described above, been previously prepared for the relay 236, the relay 6 will not be energized unless 4the correct operating bar 228 is operated; namely, the one controlling the circuit connected to the circuit prepared by operating key bar .1. In this particular instance the bar .228 is individual to the particular key lever 2 and if it is operated by the The operation of the particular received code, this indicates that the correct selection was made at the remote station, in

accordance with the code transmitted by the dispatcher. The dispatcher is now certain that in case he transmits an .operating i-m- Eulse, it will operate the proper breaker.

elay 236 is energized preparing the operating circuit or the dispatcher.

Having thus been' apprized of the'correct' ness of the selection at the" sub-station, the

dispatcher may now operate thel particular unit desired to operate, by closing the key 239. It will be noted thatthe selecting code was transmitted over a circuit completed over the back contact and armature 64. When the selection, however, has been properly made as evidenced by energization of the relay 236, the armature 64 is moved into engagement with its front contact preparing the circuit to key 239 for the operation desired andthe dispatcher may now o erate the selected unit by closing this key. t will be noted that the closing of the key 239 transmits an impulse of the opposite polarity .from that transmitted by the selecting code and accordingly the relays 65 at the dispatchers office and 82 at the sub-station will not be energized inasmuch as they are so biased that their impulses merely tend to 'maintain the armature in the bias position already maintained by their respective sprmgs.

At the substation, operation of the bar 112 by the selecting code, not only prepares the individual circuit to the particular power unit desired to be operated, but also switches the vsignaling circuit from armature 69 and its contact 144 to engagement with contact 145, thereby connecting the polar operating relay 153 in the line circuit. This relay, it will be noted, is biased oppo- 'sitely from the other polar 'relays in the line circuit so that the impulse of the opposite polarity such as issue when the operator\depresses the key 239 while not operating thepolar relays 65 and 82, will operate the polar relay 15,3 to move its armature 152 into engagement with its contact completing thel prepared selecting circuit to the power -unit desired, in this case, the tripping coil The tripping of the circuit breaker automatically operates a code transmitter by rotatingthe cam disk 173 for transmitting a code combination of impulses over thev signaling line. Batteryv 246 at the `sub-'station` and 241being in series, currents ofincreased value .are'transmitted Although this cur# rent will operate the polar relay 153, it will obviously have no further eiect inasmuch as,

it merely continues energizingthe trip coil 147. At the'dispatchers oiiice, however, theimpulses will operate the relay' 247 which is marginal and accordingly was not operated by the operate impulses troml battery 241 -icb alone. Energization of relay 247 in turn operates the answer back recorded 249 which is of a well known type employed in the telegraph art.

It will be clear that not only the apparatus units located at the first sub-station may be thus operated, but also apparatus units located at the sub-station at which the polar relay 72 is located. Since the number of operations which may be made, depends merely upon the number of impulses in each code, any practical number of selections can be made. Certain of these selections can be completed at the first sub-station and others at the second sub-station associated with the polar relay T2. Tlie'armature T3 is moved into engagement with its front contacts in the same manner as the armature 14e-l moves into engagement with its right hand contact llo for completing a circuit to the operating polar-relay 260 at t-he second sub-station.

Similarly, the signaling line can be extended through other sub-stations for selections thereat as desired. It will be evident from this that a single continuous circuit can be employed for making selections at a plurality of sub-stations.

It will be noted that con'densers such as 277,

278. E279 and 281 are connected across the armature contacts for the purpose of preventing arcing during the operation of the contacts. inasmuch as the present system is particularly adapted for transmission of current of telegraph magnitude thereby making the system considerably more rugged than has heretofore been possible. lVindings Q03 and Q82 are connected in the circuit for preventing a short circuiting of the batteries.

Although a separate selecting circuit is identify for the dispatcher the selection made yli'efore thc selected unit is operated and provides answer back signals operated in accordance with the particular unit operated and its particular operation to apprize the dispatcher of the conditions of the operated units.

Although this invention is disclosed as lapplied to a specific arrangement. it will be understood that the invention has broader application and may be applied in numerous other manners.

Having shown and described the preferred embodiment of my invention, it will be apparent that many equivalents will present themselves to those skilled in the art. The present invention is not limited to the use of the specific embodiment in the specific arrangement. shown. Therefore, what is desired to be secured by Letters Patent and is claimed as new is:

1. In a supervisory control system. a control station, a remote station, a plurality of devices at said remote station to be controlled from the control station over said line, a rotary start stop code transmitter and a rotary start stop code receiver at each of Vsaid stations normally in operative relation with said signaling line, means for operating said code transmitter at said control station for transmitting a code combination of impulses to said remote .station over said line, means controlled b v the transmitter at said control station for preventing the operation of said receiver 'thereat during the transmission of lat said remote station is responsive to said code for conditioning one of said devices 'thereat for operation and means including the code transmitter at the remote station for transmitting a. verifying code to said control station over said line in accordance with said device selected, means at said control station responsive to said code for operating the receiver thereat to verify said selection, means at said remote station for preventing the operation-of said receiver thereat during the transmission of said verifying code and means at said control station for operating said selected' device at said remote station.

2. In a signaling system, a control station, a remote station, a plurality of apparatus units at said remote station, a signaling line connecting said stations, relay means connected in said signaling line, permutation trolled by one of said devices for conditioningl an apparatus unit at the remote station for operation, and for starting and variably operating said code transmitter thereat, means controlled by said code transmitter for transmitting code combinations of impulses over said signaling line through said line relay and means whereby said permutation mechaifo,

nism thereat is non-responsive to'said "code combinations of impulses. 5

3. In a signaling system, a control system, a remote station, a plurality of apparatus units at said remote station, a signaling line connecting said stations, relay means connected in said signaling line, permutation mechanism at said remote station, electromagnetic means controlled by said relay means for variably operating said 'permuf tation mechanism in accordance with received code combinations of impulses, a code transmitter at said remote station, said code transmitten and said permutation mechanism being normally in a noni1perating condition, means responsive to the said rela means for startin said permutation mec anism into operation, a plurality 4 of devices, means controlled by said permutation mechanism for variably operating one of said devices, means controlled by one of said devices for conditioning an apparatus unit at the remote station `for operation and for starting into operation and variably operating said code transmitter, means controlled by said code transmitter for transmitting code combinations of impulses oversaid signaling'line through said relay means, means whereby said permutation mechanism at said remote station is non-responsive to said code combinations of impulses and permutation means at said control station responsive to said impulses for variably operating a signaling device in accordance with iai the received code.

4. In a signaling system,a control-station, a remote station, a plurality of Vapparatus units at said remote station, a signalingvdevice at said control station, a signaling line 40 connecting said stations, relay means con-v nected in said signaling line, permutation mechanism at said remote station, electromagneticmeans controlled by said relay Y, means for variably operating said'permuta-y lsaid permutation .mechanism for -variably operating one of said devices, means controlled by one of said devices for c0nditio`n ing anvapparatus unit .at the remote station for operation and for starting and-variably operating said code transmitter, means controlled by said code transmittery for transmit- 'ting code combinations of impulses in accordv ance with th'e selection made over said signaling. line through-said Arelayiineans, 4means whereby said permutation mechanism at said remote, station is non-'responsi'y st-*impulses received byV igeemis' i combinations of im ulses, permutation meansv at said control station responsive to said impulses for variably operating said signaling^`-`` device thereat in accordance with the received code, relay means connected in vsaid signaling line at said control station,` electromagnetic means responsive to said last mentioned relay means for variably o eratin said permutation mechanism at sai contro station in accordance with received code indicating the selections made at the remote station, a code transmitter for transmitting code combinations of impulses for variablyv operating the permutation mechanism at said l remote station and means whereby said code' receiver at said control station is rendered non-responsive to the code transmitted bysaid code transmitter thereat. l 5. In a signaling system, a control station,

an operating key at said control station, a

remote station, apparatus units and an operating means at said remote station, a device at said control station for each of said units, Y

a si aliiioline connectin said stations a rotatable code transmitter and receiver at each of said stations, said transmitter and receiver being normally in a non-operating lcondition, means responsive to the' operation ofl one of said devices for vstarting said code transmittenthereat into rot-ation, means controlled by said lcode transmitter for transmitting code combinations vof impulses over said signaling line, means whereby said code i receiver at said control station is rendered non-responsive to said code combination, means responsive to the impulses of said code combination for releasingsaid code receiver at said remote. station, means whereby said ico code receiver in response to said code combination of impulses received over said sig naling line conditions one of said apparatus units for operation and simultaneously starts said transmitter thereat into operationy for transmitting a code combination of conditions in accordance with the'selection made, means responsive to the operation. of said `code transmitter thereat for releasing said code receiver at said lcontrol station into 'rotation, means whereby said code receiver at.

said remote vstation is rendered nonresponsive to said transmitted code, means at said receiving station -1 responsive vto- .the variable operation of said code t re r 4ceiver thereat "for making a selection r means whereby if said codereceived agrees.

with the code transmitted vsaid operating key 1 by said operating key oroperating said; op

is rendered operatige and means controlled' erating means at said remote 4statioirfor,"70p

i erating said Iconditioned, apparatuglnit. v c 1 6, I n a signaling system, a ntpoi magi); g an: operating key-at said control statioma remote station, ap aratus units and an ,oper

.atin -means at said remote station, la device@` at sald'control station .for each of saiduiiits,l

signaling means at said control station for indicating the condition of said units, a signaling line connecting said stations, a rotatable code transmitter and receiver at each of said stations, said transmitter and receiver being normally in a non-operating condition, means responsive to the operation of one of said devices for starting said code transmitter thereat into rotation, means controlled by said code transmitter for transmitting code combinations of impulses over said signaling line, means whereby said code receiver at said control station is rendered non-responsive to said code combination, means responsive to the impulses of said combinations for releasing said code receiver at said remote station, meansl whereby said code receiver in response to said code combination of impulses received over said signaling line conditions one of said apparatus units for operation and simultaneously starts said transmitter thereat into operation for transmitting code combinations of conditions in accordance with the selection made, means responsive to the operation of said code transmitter thereat for releasing said code receiver at said control station into rotation. means whereby said code receiver at said remote station is rendered non-responsive to said transmit-ted code, means at said receiving station responsive to the variable operation of said code receiver thereat for making a selection` means whereby7 if said code received agrees with the code transmitted said operating key is rendered operative, means controlled by said operating key for operating said operating means at said remote station for operating said conditioned apparatus unit and means whereby responsive to the operation of said unit said signaling means is operated at said control station in accordance with the unit operation..

7. In combination, a control station. a remote station, a plurality of devices at said remote station to be selectively controlled from said control station, transmitting and receiving means at each of said stations, operating means atsaid control station, a signaling line connecting said stations` said signaling line being normally connected to said transmitting means at said control station and to said receiving means at the remote stations, means including said transmitting means at said transmitting station for variably operating said receiving means at said remote station, means responsive to the operation of said receiving;r means at said remote station for selecting one of said devices for operation, operating means at said remote station normally disconnected from said signaling line, said receiving means being simultaneously operated in response to said control station transmitting means to connect said operating means to said signaling line, operating means at said control station, said transmitting means at said remote station operating in response to said selection of a unit for directly operating said receiving means at said control station over said signaling line, said control station receiving means being responsive to control from said remote station transmitting means for switching said signaling .line from said transmitting means at said control station to saidoperat-ing means tliereat, means including said operating means and said signaling line for operating said operating means at said remote station and means responsive to the operating means at said remote station for operating said selected device.

8. In a supervisory control signal; a control station; a remote station; a signaling line connecting said stations; a line switch therefor; electromagnetic means for operating said switch; a plurality ofv apparatus units at said remote station: a key bank comprising a plurality of key levers at said control station; a normal non-operating code transmitter at said control station normally connect-ed to said line; means controlled by the operation of any one of said key levers for starting said code transmitter into operation to transmit code combinations of signaling conditions over said line to said remote station in accordance with the operated ,key lever; meansl responsive to the operation of said key lever for locking said key lever in'operated position and the. remaining key levers in non-operated position and for preparing a circuit for said line switching electro-magnetic means; means at said remote station responsive to said received code combination for selecting a unit for operation; means at said remote station responsive to the selection of one of said units for transmitting a code combination of signaling conditions to said control station in accordance with the selection made thereat; a code rcceiver at said control station responsive to said received code combinations of signaling conditions for completing the circuit of said line switching means; operating means; means `controlled b v said switching means for disconnecting said control station transmitter from said signaling line and switching said. line to said operating means; means including said operating means operative over said switched line for operating said selected apparatus unit.

9. In a supervisory .control system: a control station; a remote station; a signaling line connect-ing said stations; a line switch therefor: electro-magnetic means for operating said switch; a plurality of apparatus units at said remote station: a key bank comprising a plurality of key levers at said cont-rol station; a normal non-operating code transmitter at said control station normally connected to said line; means controlled by the operation of any one of said key levers for starting saidco'de transmitter into operation to transmit code combinations of slgnaling conditions over said line to said remote station in accordance with the operated key lever; means responsive to the^operation of said key lever for locking said key lever in operated position and remainingkey levers in non-operated position and for preparing a circuit for sadline switching electro-magnetic means; means at said remote station responsive tocsaid received code combination for selecting a unit for operation; means at saidy remote station responsive to the selection of one of said units for transmitting a code combination of ,signaling conditions to said control station in accordance with the selection made thereat; a code receiver at said control stationresponsive to said received code combinations of signaling conditions for completing the circuit of saidl line switching means; operating means; means controlled by said switching means for disconnecting said control station transmitter from the signaling line and switching said line to vsaid operating means; means `including said operating means operative over said switched line for operating said selected apparatus unit, and means responsive to the operation of said unit for indicating said operation at said control station.

10. In a supervisory control system; a control station; a remote station; a single signaling line connecting said stations; normal v Asaid remote station into operation; means for operating a single electro-magnet at said remote station responsive to sald received Code combinations of impulse conditions for variably operating saidreceiver in accordance with the received f'code combination; means controlled by said code receiver for selecting one of said apparatus units for operation; means controlled by said selection for starting said code transmitter at said remote station into operation to transmit a-code combination of signaling conditions over said signaling line to said control station in accordance with the selection made; and a single electro-magnet at said control station responsive to code combinations of impulse 'conditions for variably operating said control receiver at'said control station in accordance with the received code for indicating the selection made at the remote station.

11. Inl a supervisory control system; a con-` at said control station; operating means at v said control station; means controlled by the operation of any one of said key levers for starting said transmitting apparatus thereat into operation to transmit a start condition and a code combination of s1 aling conditions over said line in accor ance with the key lever operated; means responsive to a start condition for starting said transmitting apparatus at said remotestation into operation; a single electro-magnet at said remote station responsive to said received code combinations of impulse conditions forl variably operating said receiver in accordance with the received code combinations; means controlled by said receiving apparatus for selecting one of said apparatus units for operation; means controlled by said selection for starting said transmitting apparatus at said remote station into operation to transmit a code combination of signaling conditions over said signaling line to said control station in accordance with the selection made; a single electro-ma et at said control station responsive to c e combinations of impulse conditions for variably operating said receiving apparatus at said control station -in accordance'with the received code combination for indicating the selection made at the remote station; a switching'means for switching said signaling line from said transmitting apparatus at said control station to said operating means; a plurality of electric circuits for said switching means one for each of said key levers; means whereby each of said circuits is prepared in l response to the operation of its' associated key lever; and means whereby said prepared circuit is completed in response to the operation of the associated receiving apparatus whereby said switching circuit is completed only if' said received code combination indica-tes that the remote selection was madel in accordance with the operated key.

12. In a supervisory control system; a control station;a-remote station; a single signali ing line connecting said stations; normal non-operating start stop transmitters and rel celvers at eaclrof said stations, said transmitters being normally connected to said line;

a plurality of apparatusnnitsat said remote .'station; operatlng key levers individual to each apparatus unit at said control station; operating means at said control station; i

means controlled by the operation of any one of said key levers for starting said code transmitter thereat into operation to transmit a start condition and a code combination of signaling conditions over said line in accordance with the key lever operated means responsive to a start condition for starting said receiver at said remote station into operation a single electro-magnet at said remote station responsive to said received code combinations of impulse conditions for variably operating said receiver in accordance with the received code combinations; means cotitrolled by said receiver for selecting one of said apparatus units for operation; means controlled b v said selection for starting said transmitter at said remote station into operationto transmit a code combination of signaling conditions over said signaling line to said control station in accordance with the selection made; a single electro-magnet at said control station responsive to code combinations of signaling conditions for variably op'- erating said control receiver at said control station in accordance with the received code combination for indicating the selection made at the'relnote station; switching means for switching said signaling line from said code transmitter to said operating means; a plurality of electric circuits for said switching means one for each of said ley levers; means whereby each of said circuits is prepared in response to the operation of its associated key lever; means whereby said prepared circuit is completed in response to the operation or" the associated receiving means whereby said switching circuit is completed only if said received code combination indicates that the remote selection made was made in accordance with the operated key; and means controlled over said switched circuit for operating said selected unit.

13. In a. supervisory control system; a control station; a remote station; a single signaling line connecting said stations; normal non-operating start stop transmitters and receivers at each of said stations, said transmitters being normally connected to said line;

-a plurality of apparatus units at said remote station; operating key levers individual to each apparatus unit at said control station; operating means at said control station; means controlled by the operation of any one of said key levers for starting said code transmitter thereat into operation to transmit a start condition and a code combination of signaling conditionsover said line in accordancewith the key lever operated; means responsive to a start condition for starting said receiver at said remote station into operation; a single electro-magnet at said remote station responsive to said received code combinatins of signaling conditions for variably operating said receiver in accordance with the received code combination; means controlled by said receiver for selecting one of said apparatus units for operatic-n; means controlled by said selection for starting said transmitter at said remote station into operation to transmit a code combination of signaling conditions over said signaling line to said control station in accordance with the selection made; a single electro-magnet at said control station responsive to code combinations of impulse conditions for variably operating said control receiver at said control station in 'accordance with the received code combination for indicating the selection made at the remote station; switching means for switching said signaling line from said code transmitter to said operating means; a plurality of electric circuits for said switching means one for each of saidkey levers; means whereby each of said circuits is prepared in response to the operation of its associated key lever; means whereby said prepared circuit is completed in response to the operation of the associated receiver whereby said switching circuit is completed only if the received code combination indicates that the remote selection made was made in accordance with the operated key; means controlled over said switched circuit for operating said selected unit; and means-controlled over. said switched circuit in response to the operation of said unit for indicating said operation at said controlled station.

14. In a supervisory control system; a control station; a remote station a start stop code transmitter and code receiver at each of said stations; an electro-magnet for controlling said start stop receiver at each of said stations; a single circuit connecting said transmitters and receivers including means whereby said start stop receivers cannot be started into operation while the transmitter at their respective stations is yin operation; a plurality of apparatus units at said remote station; operating keys individual to each of said apparatus units at said control station; means controlled by the operation of any one of said keys for starting said code transmitter at said control station into operation to transmit a code combination of signaling conditions over said circuit in accordance with the key operated; means at said remote station responsive to said received code combination for operating said receiving magnet thereat whereby said receiver thereat is variably operated in accordance with the received code and said transmitter thereat is correspondingly operated to return a verification signal to the receiver at said control station; and means controlled b v the received code combination at said remote station over said line for selecting one of said units for operation.

115. In a supervisory'control system; a control station; a remote station; a start stop code transmitter and code receiver at each of said stations; an electro-magnet for controlling said'start stop receiver at each of said stations; a single circuit therefor controlled by the code transmitter thereat whereby said start stop receivers cannot be started into operation while said transmitter thereat is in operation; a plurality of apparatus units at said remote station operatingkeys individual to each of said apparatus units at said control station; means controlled by the operation of any one of said keys for startingsaid code transmitter at said controlstation into operation to transmit a code combination of sivnaling conditions over said line in accor ance'with the key operated; means at said remote station responsive to said received code combination for operating said receiving .magnet thereat whereby said receiver thereat is variably operated in accordance with the received code; means controlled by the received code combination for selecting one of said units for operation; means responsive to the selection of said'unit for starting said code transmitter at said remote station into operation; means controlled by said remote transmitter for transmitting a code combination of signaling conditions over said line in accordance with the selected unit; means at said control station responsive to said received code combinations of impulse conditions for variably operating said receiver magnet thereat; and means controlled by said receiver in accordance with the operation of said magnet for indicating'said selec'- tion. o v 16. In a supervisory control system; a control station; a remote station; a signaling line connecting said stations; a start stop code transmitter and code receiver at each of said stations normally connected for transmission over said line; an o erating means at said control station; an e ectro-magnet for controlling'said start stop receiver at each of said stations; a circuit therefor controlled by the code transmitter thereat whereb said start stop receivers cannot be starte into loperation while said transmitter thereat is in operation; a plurality of apparatus units at said remote station; operating keys individual to each of said apparatus units at said control station; means controlled by the operation of any one of said keys for starting said code transmitter at said control station into operation to transmit a code combination of signaling conditions in accordance with the key operated; means-at said :remote station responsive to said received code combination for operating said receiving magnet to actuate said receiver in accordance with the received code; means controlled by the received code combination for selecting one of said units for operation; means responsive to the selection of said unit for starting said code transmitter at said remote station into operation; means controlled by said remote transmitter for transmitting a code combination of signaling conditions in ac' cordance with the selected unit; means at said' v control station responsive to said received code combinations of signaling conditions for variably operating said receiver magnet l thereat; means controlled by said receiver in accordance with the operation ofsaid magnet for indicating said selection; and means operative only in the event that said selection agrees with said operated key lever for switching said line to said operating means.

17. In a supervisory' control system; a con! trol station; a remote station; a signaling line connecting said stations; a start stop codel transmitter and code receiver at each of said stations normally connected for transmission over said line; an operating means at said control station; anelectro-magn'et for controlling said start stop receiver at each of said stations; a circuit therefor controlled by the code transmitter thereat whereby said start stop receivers cannot be started into operation while said transmitter thereat is in operation; a plurality7 of apparatus units at said remote station; operating keys individual to each of said apparatus units at said control station; means controlled by the operaticin of any one of said keys for starting said code transmitter at said control station into operation to transmit a 'code combination of signaling conditions in accordance with the key operated; means at said remote station responsive to said received code combination for operating said' receiving magnet thereat whereby said receiver thereat is variably operated in accordance with the-received code; means controlled by the received code combination for selecting one of said units for operation; means responsive to nthe selection of -said unit for starting said code transmitter at said remote stationf into operation; means controlled by said remote transmitter for transmitting a code combination of impulse conditions in accordance with the selected unit; means at said control station,

responsive to said receivedl codev combinations of impulse conditions for variably operating said receiver magnet thereat; means controlled by saidl receiver accordance with the operation of said magnet for indicating said selection; means operative only in the event that ksaid selection agrees with said operated key lever for switching said line to said operating means; and means controlled :over said vswitched line for operating said selected unit.

18. In a supervisory control system; a con trol system; a remote station; a signaling line connecting said stations; a start stop 'code transmitter and code receiver at each of sai said stations; a circuit for said magnets at' d stations normally connected for transmissioneach station controlled by the code transmitter thereat whereby said start stop receivers cannot be started into operation while said transmitter thereat is in operation; a plurality of apparatus units at said remote station;

operating' keys individual to each of said apparatus units at said control station; means controlled by the operation of any one of said keys for starting said code transmitter at the control station into operation to transmit a code combination of signaling conditions in accordance with the key operated;

means at said remote station responsive tor received code combinations for operating said receiving magnet thereat whereby the receiver thereat is variably operated in accordance with the received code; means controlled by the received code combination for selectingr one of said units for operation; means responsive to the selection of said unit for starting` said code transmitter at said remote station into operation; means controlled by said remote transmitter for transmitting a code combination of impulse conditions in accordance with the selected unit; means at said control station responsive to said received code combinations of impulse conditions for variably operating; said receiver magnet thereat; means controlled by said receiver in accordance with the operation of said magnet for indicating said selection; means operative only in the event that said selection agrees with said operated key lever for switching; said line to said operatin means; meanscontrolled over said switche line for operating said selected unit; and means controlled in accordance with the operation of said selected unit and operative over said switching` line for indicating said operation at said control station.

In testimony whereof I ax my si ature.

EDWARD E. KLEINSCHM DT. 

